Remove algo factory, engines, global RNG, global state, etc.

Convert all uses of Algorithm_Factory and the engines to using Algo_Registry

The shared pool of entropy sources remains but is moved to EntropySource.
With that and few remaining initializations (default OIDs and aliases)
moved elsewhere, the global state is empty and init and shutdown are no-ops.
Remove almost all of the headers and code for handling the global
state, except LibraryInitializer which remains as a compatability stub.

Update seeding for blinding so only one hacky almost-global RNG
instance needs to be setup instead of across all pubkey uses (it uses
either the system RNG or an AutoSeeded_RNG if the system RNG is not
available).

1 files changed, 215 insertions, 0 deletions

diff --git a/src/lib/base/algo_registry.h b/src/lib/base/algo_registry.h
new file mode 100644
index 000000000..9582180bd
--- /dev/null
+++ b/src/lib/base/algo_registry.h
@@ -0,0 +1,215 @@
+/*
+* (C) 2014,2015 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_ALGO_REGISTRY_H__
+#define BOTAN_ALGO_REGISTRY_H__
+
+#include <botan/types.h>
+#include <functional>
+#include <stdexcept>
+#include <mutex>
+#include <vector>
+#include <map>
+#include <unordered_map>
+
+namespace Botan {
+
+template<typename T>
+class Algo_Registry
+   {
+   public:
+      typedef typename T::Spec Spec;
+
+      typedef std::function<T* (const Spec&)> maker_fn;
+
+      static Algo_Registry<T>& global_registry()
+         {
+         static Algo_Registry<T> g_registry;
+         return g_registry;
+         }
+
+      void add(const std::string& name, const std::string& provider, maker_fn fn, byte pref)
+         {
+         std::unique_lock<std::mutex> lock(m_mutex);
+         m_algo_info[name].add_provider(provider, fn, pref);
+         }
+
+      std::vector<std::string> providers_of(const Spec& spec)
+         {
+         std::unique_lock<std::mutex> lock(m_mutex);
+         auto i = m_algo_info.find(spec.algo_name());
+         if(i != m_algo_info.end())
+            return i->second.providers();
+         return std::vector<std::string>();
+         }
+
+      T* make(const Spec& spec, const std::string& provider = "")
+         {
+         maker_fn maker = find_maker(spec, provider);
+
+         try
+            {
+            return maker(spec);
+            }
+         catch(std::exception& e)
+            {
+            throw std::runtime_error("Creating '" + spec.as_string() + "' failed: " + e.what());
+            }
+         }
+
+      class Add
+         {
+         public:
+            Add(const std::string& basename, maker_fn fn, const std::string& provider = "builtin", byte pref = 128)
+               {
+               Algo_Registry<T>::global_registry().add(basename, provider, fn, pref);
+               }
+
+            Add(bool cond, const std::string& basename, maker_fn fn, const std::string& provider, byte pref)
+               {
+               if(cond)
+                  Algo_Registry<T>::global_registry().add(basename, provider, fn, pref);
+               }
+         };
+
+   private:
+      Algo_Registry() {}
+
+      maker_fn find_maker(const Spec& spec, const std::string& provider)
+         {
+         std::unique_lock<std::mutex> lock(m_mutex);
+         return m_algo_info[spec.algo_name()].get_maker(provider);
+         }
+
+      struct Algo_Info
+         {
+         public:
+            void add_provider(const std::string& provider, maker_fn fn, byte pref = 128)
+               {
+               if(m_maker_fns.count(provider) > 0)
+                  throw std::runtime_error("Duplicated registration of '" + provider + "'");
+
+               m_maker_fns[provider] = std::make_pair(pref, fn);
+               }
+
+            std::vector<std::string> providers() const
+               {
+               std::vector<std::string> v;
+               for(auto&& k : m_maker_fns)
+                  v.push_back(k.first);
+               return v;
+               }
+
+            void set_pref(const std::string& provider, byte val)
+               {
+               m_maker_fns[provider].first = val;
+               }
+
+            maker_fn get_maker(const std::string& req_provider)
+               {
+               maker_fn null_result = [](const Spec&) { return nullptr; };
+
+               if(req_provider != "")
+                  {
+                  // find one explicit provider requested by user or fail
+                  auto i = m_maker_fns.find(req_provider);
+                  if(i != m_maker_fns.end())
+                     return i->second.second;
+                  return null_result;
+                  }
+
+               size_t pref = 255;
+               maker_fn result = null_result;
+
+               for(auto&& i : m_maker_fns)
+                  {
+                  if(i.second.first < pref)
+                     {
+                     pref = i.second.first;
+                     result = i.second.second;
+                     }
+                  }
+
+               return result;
+               }
+         private:
+            std::unordered_map<std::string, std::pair<byte, maker_fn>> m_maker_fns; // provider -> (pref, creator fn)
+         };
+
+      std::mutex m_mutex;
+      std::unordered_map<std::string, Algo_Info> m_algo_info;
+   };
+
+template<typename T> T*
+make_a(const typename T::Spec& spec, const std::string provider = "")
+   {
+   return Algo_Registry<T>::global_registry().make(spec, provider);
+   }
+
+template<typename T> std::vector<std::string> providers_of(const typename T::Spec& spec)
+   {
+   return Algo_Registry<T>::global_registry().providers_of(spec);
+   }
+
+template<typename T> T*
+make_new_T(const typename Algo_Registry<T>::Spec&) { return new T; }
+
+template<typename T, size_t DEF_VAL> T*
+make_new_T_1len(const typename Algo_Registry<T>::Spec& spec)
+   {
+   return new T(spec.arg_as_integer(0, DEF_VAL));
+   }
+
+template<typename T, size_t DEF1, size_t DEF2> T*
+make_new_T_2len(const typename Algo_Registry<T>::Spec& spec)
+   {
+   return new T(spec.arg_as_integer(0, DEF1), spec.arg_as_integer(1, DEF2));
+   }
+
+template<typename T> T*
+make_new_T_1str(const typename Algo_Registry<T>::Spec& spec, const std::string& def)
+   {
+   return new T(spec.arg(0, def));
+   }
+
+template<typename T> T*
+make_new_T_1str_req(const typename Algo_Registry<T>::Spec& spec)
+   {
+   return new T(spec.arg(0));
+   }
+
+template<typename T, typename X> T*
+make_new_T_1X(const typename Algo_Registry<T>::Spec& spec)
+   {
+   std::unique_ptr<X> x(Algo_Registry<X>::global_registry().make(spec.arg(0)));
+   if(!x)
+      throw std::runtime_error(spec.arg(0));
+   return new T(x.release());
+   }
+
+#define BOTAN_REGISTER_NAMED_T(T, namestr, type, maker)                 \
+   namespace { Algo_Registry<T>::Add g_ ## type ## _reg(namestr, maker); }
+#define BOTAN_REGISTER_T(T, name, maker) \
+   namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, maker); }
+#define BOTAN_REGISTER_T_NOARGS(T, name)                                \
+   namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, make_new_T<name>); }
+#define BOTAN_REGISTER_T_1LEN(T, name, def) \
+   namespace { Algo_Registry<T>::Add g_ ## name ## _reg(#name, make_new_T_1len<name, def>); }
+
+#define BOTAN_REGISTER_NAMED_T_NOARGS(T, type, name, provider) \
+   namespace { Algo_Registry<T>::Add g_ ## type ## _reg(name, make_new_T<type>, provider); }
+#define BOTAN_COND_REGISTER_NAMED_T_NOARGS(cond, T, type, name, provider, pref) \
+   namespace { Algo_Registry<T>::Add g_ ## type ## _reg(cond, name, make_new_T<type>, provider, pref); }
+#define BOTAN_REGISTER_NAMED_T_2LEN(T, type, name, provider, len1, len2)     \
+   namespace { Algo_Registry<T>::Add g_ ## type ## _reg(name, make_new_T_2len<type, len1, len2>, provider); }
+
+// TODO move elsewhere:
+#define BOTAN_REGISTER_TRANSFORM(name, maker) BOTAN_REGISTER_T(Transform, name, maker)
+#define BOTAN_REGISTER_TRANSFORM_NOARGS(name) BOTAN_REGISTER_T_NOARGS(Transform, name)
+
+}
+
+#endif